1. Field of the Invention
The present invention relates to a method of aligning a photomask with a base material in manufacturing steps of a printed circuit board, and a method of manufacturing the printed circuit board.
2. Description of the Background Art
In a printed circuit board, a conductor layer having a given pattern is formed on an insulating layer. Application of a photoresist (hereinafter abbreviated as a resist), exposure processing and development processing for forming the conductor layer in a given pattern, for example, are performed in manufacturing steps of the printed circuit board. The resist is applied on the conductor layer, thereby forming a resist layer on the conductor layer, for example. In the exposure processing, a surface of the resist layer is irradiated with light through a photomask. Thus, the resist layer is exposed in a pattern of the photomask. The development processing is then performed, so that the resist layer having the given pattern (hereinafter referred to as a resist pattern) is formed on the conductor layer.
In this state, a region of the conductor layer excluding a region below the resist pattern is removed by etching, for example, and the resist pattern is subsequently removed. In this manner, the conductor layer is formed in the given pattern.
During the foregoing exposure processing, it is necessary to detect a region to be exposed (hereinafter referred to as an exposure region) of the resist layer on a base material such as the conductor layer, and align the exposure region and the photomask with each other. For aligning the base material, an alignment mark for exposure is provided in the base material, and the base material is moved such that the alignment mark is positioned in a given position. When the base material is aligned, the base material is photographed by a camera, and an image including the alignment mark is processed, so that a position of the alignment mark is detected (see JP 5-217843 A, for example).
In recent years, reduction in time for the exposure processing has been required in order to improve manufacture efficiency of the printed circuit board. Therefore, the exposure region and the photomask need to be efficiently aligned with each other.